Roof Drain Sizing Ontario

According to the chart for 1 8 slope per 12 of pipe for 5 000 square feet of roof area with a 6 per hour of rainfall the required pipe size is 8.

Roof drain sizing ontario.

Divide total roof area by area found in step 3 to obtain the number of drains required example. The drains should be equally spaced and located symmetrically about the roof. Equals 32 6 or 33 drains required. 2 with 2 in.

Enter table 1108 1 until you find a diameter pipe that will carry 2 344 sq ft. 3 where the height of the parapet is more than 150 mm or exceeds the height of the adjacent wall flashing a emergency roof overflows or scuppers described in clause 2 c shall be provided and b there shall be a minimum of two roof drains. Urinal a pedestal siphon jet or blowout type. A minimum 4 inch vertical drain is required.

Roof drain construction details. Take the roof s total square footage and divide by the total square footage handled by one drain. Sizing a roof water drain. Each drain can handle 4 600 sq.

For building when we size the roof drain the national plumbing code has form to select the roof drain size based on 25mm 15min storm for most area in ontario. To convert to an area for a 4 inch per hour rainfall to enter table 1108 1 do this. An extensive list of easy to view details is also provided on the hy tech website. When we size the storm sewer water flow is from rational method formula q cia i mm hr rainfall intensity is from city s idf curve.

For guidelines on placement and sizing of roof drains see fm global s ds 1 54 roof loads for new construction data sheet. The first step in sizing a roof drain is to calculate the surface area of the roof that the drains will be covering as well as the average hourly rainfall rate at the building location. E there is at least one drain for each 900 m 2. To size the vertical roof drain for the same parameters 5 000 square feet of room area and 6 per hour of rain consult table 1106 2 figure 3.

The next step is to determine each roof area that will be served by a separate leader drain pipe scupper or downspout. Sizing data for conventional drainage. Divided by the 4 600 sq. Each vertical drain must carry 2 500 sq ft of roof area at 3 75 inches per hour of rainfall.

You have to sign up in order to view data sheets on the fm global website but. Sink a domestic and other small type with or without garbage grinders single double or 2 single with a common trap. Or 12 drains required. 2 500 4 x 3 75 2 344 sq ft.

If water proof deck covering thickness is greater or less than 3 16 lip dimension must be specified. When the dx flange is required on drains other than those shown in this section the prefix dx must be used with the figure number. 1 with 1 in. Shower drain a from 1 head.

3 with 3 in. 1 b from 2 or 3 heads. 50 000 4 400 11 36. 3 c from 4 to 6 heads.